ConvexShadpe problem.

I'm developing now a Mesh to ConvexShape.
The first goal was to extract the Edges for the mesh. I use getMeshInformation(...) from
http://www.ogre3d.org/wiki/index.php/RetrieveVertexData , the second one.
that function return:
- all vertices
- all indexes (triangles)

with a little code a get edges like that:

bool notRepeated(std::vector<Ogre::Vector3>* verts, Ogre::Vector3& A1, Ogre::Vector3& A2)
{
for(int i=0; i<verts->size(); i+=2)
{
if (
( (*verts)[i] == A1 && (*verts)[i+1] == A2 )
||
( (*verts)[i] == A2 && (*verts)[i+1] == A1 )
)
{
OgreLog(Ogre::String("REPEATED"));
return false;
}
}
return true;
}

std::vector<Ogre::Vector3>& getMeshEdges(Ogre::Mesh* mesh)
{
size_t vertex_count,index_count;
Ogre::Vector3* vertices;
unsigned long* indices;

getMeshInformation(mesh,vertex_count,vertices,index_count,indices,
Ogre::Vector3::ZERO,Ogre::Quaternion::IDENTITY,
Ogre::Vector3(1,1,1));

std::vector<Ogre::Vector3>* out=new std::vector<Ogre::Vector3>();

OgreLog(Ogre::StringConverter::toString(index_count));
OgreLog(Ogre::StringConverter::toString(vertex_count));

for(size_t i=0; i<index_count; i+=3)
{
if(notRepeated(out,vertices[indices[i]],vertices[indices[i+1]]))
{
out->push_back(vertices[indices[i]]);
out->push_back(vertices[indices[i+1]]);
}
if(notRepeated(out,vertices[indices[i]],vertices[indices[i+2]]))
{
out->push_back(vertices[indices[i]]);
out->push_back(vertices[indices[i+2]]);
}
if(notRepeated(out,vertices[indices[i+1]],vertices[indices[i+2]]))
{
out->push_back(vertices[indices[i+1]]);
out->push_back(vertices[indices[i+2]]);
}
}


delete[] vertices;
delete[] indices;

return *out;

}
(I'm not worry about the memory leak yet)

So with that code applied to a cube give you a vector with 32 points (16 edges) that's correct, but when create the ConvexShape Crash (no assertions) :S



So, someone have a Mesh -> ConvexShape vector.

Hey, Good work.

But there is a hard limit on how many vertices a convex shape is, and I think that is 32 or 64, also you don't have to supply the edges, or indices. Just the vertices.

Ok, as allways I dont search enought in the forum (related post I missed: http://www.ogre3d.org/phpBB2addons/view ... light=link )

I made a Ogre::Mesh to std::vector<Ogre::Vector3> (vertices only no repeated)

Now works fine in Release Mode, and don't work in debug. So it will be a pain to debug my program in release without memory management.

Is there any trick to run ConvexShapes in Debug?


CODE:
void getMeshInformation( const Ogre::Mesh* const mesh,
const Ogre::Vector3 &position,
const Ogre::Quaternion &orient,
const Ogre::Vector3 &scale,
std::vector<Ogre::Vector3>& output)
{
bool added_shared = false;
size_t current_offset = 0;
size_t shared_offset = 0;
size_t next_offset = 0;
size_t vertex_count=0;

vertex_count = 0;

// Calculate how many vertices and indices we're going to need
for ( unsigned short i = 0; i < mesh->getNumSubMeshes(); ++i)
{
Ogre::SubMesh* submesh = mesh->getSubMesh( i );

vertex_count += submesh->vertexData->vertexCount;
}

OgreLog(Ogre::String("vertex: ")+Ogre::StringConverter::toString(vertex_count));

added_shared = false;

// Run through the submeshes again, adding the data into the arrays
for ( unsigned short i = 0; i < mesh->getNumSubMeshes(); ++i)
{
Ogre::SubMesh* submesh = mesh->getSubMesh(i);

Ogre::VertexData* vertex_data = submesh->useSharedVertices ? mesh->sharedVertexData : submesh->vertexData;

if((!submesh->useSharedVertices)||(submesh->useSharedVertices && !added_shared))
{
if(submesh->useSharedVertices)
{
added_shared = true;
shared_offset = current_offset;
}

const Ogre::VertexElement* posElem =
vertex_data->vertexDeclaration->findElementBySemantic(Ogre::VES_POSITION);

Ogre::HardwareVertexBufferSharedPtr vbuf =
vertex_data->vertexBufferBinding->getBuffer(posElem->getSource());

unsigned char* vertex =
static_cast<unsigned char*>(vbuf->lock(Ogre::HardwareBuffer::HBL_READ_ONLY));

// There is _no_ baseVertexPointerToElement() which takes an Ogre::Real or a double
// as second argument. So make it float, to avoid trouble when Ogre::Real will
// be comiled/typedefed as double:
// Ogre::Real* pReal;
float* pReal;

for( size_t j = 0; j < vertex_data->vertexCount; ++j, vertex += vbuf->getVertexSize())
{
posElem->baseVertexPointerToElement(vertex, &pReal);

Ogre::Vector3 pt(pReal[0], pReal[1], pReal[2]);

bool add=true;
for(size_t x=0; x<output.size();++x)
{
if ( output[x] == (orient * (pt * scale)) + position )
add=false;
}

if ( add )
{
output.push_back((orient * (pt * scale)) + position);
OgreLog(Ogre::String("vertex added: ")+Ogre::StringConverter::toString(pt)+Ogre::String("position: ")+Ogre::StringConverter::toString(current_offset + j));
}
}

vbuf->unlock();
next_offset += vertex_data->vertexCount;
}
current_offset = next_offset;
}
}
(not optimized yet)

Yay, well done!

But: Debug never works with that memory manager, so don't worry about it.

If you want me to add it into NxOgre, just say the word.

feel free to do it. remove OgreLog() and include it in Preview 4 ( I'm waiting the new release!!! )


I'm thinking now to do a trimesh collision for debug and ConvexShape for release, with that I have both codes so I can test the speed in release for both and I can run the program in debug so i can see the memory leaks.

Well if you want to rewrite the memory manager supplied with Ageia go ahead.

betajaen do me a favor.
Test it with Preview 4 and Physx 2.4.4 or 2.5 (if it's compatible nxOgre)

maybe it works, maybe not

I will do so in the morning.

Alright here you go, you have a choice of two


new convexShape(<vertices>, <material>, <pose>);
new convexShape(<meshname>, <material>, <pose>);


It works properly with the convexShape provided:




Fairly okay, with cube.1m.mesh




And not so well with crumple.mesh (Although I did expect PhysX to explode with 96 vertices).

I tested with a lot of vertices, around 160 but all cubes, and work.

About "crumple.mesh" it isn't a Convex mesh properly, Physx try to make a Convex Mesh more regular then the Original one, with that simplify the collision.

I will test Athenea.mesh & ogre.mesh when have time, right now my app crash when try to world->setdebug(true) ( something related with the logmanager i will search now in the forums )

It's not really to do with the amount of vertices, although I'd assume the less the better.

It's to do that it's a polyhedron; meaning that it doesn't contain any holes or indentations.

I made some progress in the new part of the code: ConvexShape LOD
That means that use a LOD level to create the Convex Shape for physics optimizations.


Here are some pics from my test.
Athnea model with 5 LODS, 60% reduction 126 vertices (using LOD 5)




Code soon.

Wow, that is pretty good.

However the stick thing should be a separate shape there.